Grass-legume mixtures for erosion control along forest roads in western Oregon

ABSTRACT—Attempts were made to identify legume species that would becompatible with grasses in roadside seeding mixtures for use in the mountainsof western Oregon. Despite successful germination and early establishment,legumes were unable to compete with grasses and largely disappeared frommost roadside stands after I year. Grass-legume seed, fertilizer, and strawmulch applied to road backslopes for the most part successfully halted ero-sion. Rates of erosion from unmulched and bare control plots during the firstyear after seeding were substantially higher on newly constructed backslopesthan on a backslope that was several years old at the time of plot installation.Results indicated that a mulch, as well as seed and fertilizer, should be placedon roadside slopes if soil erosion is to be —minimized during the first rainy sea-son following road construction. In addition, infertile subsoils failed to main-tain a viable vegetative cover and required ref ertilization 7 years after plotswere initially seeded and fertilized. Bare, unprotected roadside slopes con-tinued to erode at a rather constant rate throughout the course of the study.The loss amounted to about 0.2 inch of soil per year.